Thin film transistor liquid crystal display (TFT-LCD) devices have dominated the current flat-panel display market due to its advantages of small size, no radiation output, low manufacturing costs, and so on. A thin film transistor liquid crystal display device typically includes a color filter substrate, a thin film transistor array substrate, and a liquid crystal layer filled within the cell made by assembling the color filter substrate and the array substrate together.
The majority of TFT-LCDs is a RGB display device. Typically, the RGB display device includes a pixel unit having three color sub-pixels: a red sub-pixel, a green sub-pixel, and a blue sub-pixel. By adjusting gray values of three color sub-pixels, the color and brightness of the pixel unit can be controlled. The RGB display device includes color filters that filter the color of the backlight. This results in a relatively lower light transmission rate. To improve the brightness of the display device, it is required to have a brighter backlight, leading to a relatively high power consumption.
A RGBW display device is another type of display device that includes a pixel unit having four color sub-pixels: a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel. The RGBW display device has a relatively higher light transmission rate and relatively lower power consumption as compared to the RGB display device.